The internationally-recognised government, led by Hadi, establishes a "provisional" base in the port city of Aden in late September 2016.

Two months later, the rebels and allied forces of former president Ali Abdullah Saleh form a government of their own in Sanaa, dousing hopes of a UN-brokered national unity government.

Carnage

On September 28, 2015, an airstrike smashes a wedding hall in southwestern Mokha, killing 131 people. The coalition denies responsibility.

On August 15, 2016, coalition planes bomb a hospital in Abs, northwestern Yemen, the fourth strike in a year on a medical facility run by the non-governmental organisation Medecins Sans Frontieres (Doctors Without Borders). MSF says 19 people died and 24 were wounded.

Coalition planes have dropped banned cluster munitions and killed two times more civilians than other forces, according to the UN.

On October 8, 2016, an airstrike kills 140 people and wounds 525 others at a funeral in Sanaa. The coalition belatedly acknowledges responsibility.

Washington steps up airstrikes against al-Qaeda in the Arabian Peninsula (AQAP), which has benefitted from the chaos to gain influence.

AQAP loses territory to the Islamic State which on March 20, 2015 claims responsibility for the first time for attacks against two Shia mosques in Sanaa that kill 142 people.

A botched January 29 anti-AQAP raid by US special forces results in the deaths of a US Navy SEAL and multiple civilians – including women and children.

Famine

According to the UN, the fighting has displaced more than three million people, and more than two thirds of Yemen's population of around 18.8 million people need aid.

Some 7.3 million people are estimated to be close to starvation and 462,000 children suffer from serious malnutrition. Without $2.1 billion in international aid, the UN warns that Yemen will suffer a famine in 2017.